The present invention relates generally to torsion damping assemblies which comprise two coaxial parts mounted for relative rotation within a predetermined range of angular displacement and circumferentially acting resilient means circumferentially disposed between the coaxial parts.
As is known such a torsion damping assembly is usually part of an automotive clutch plate. One of the coaxial parts then comprises friction disc adapted to be fixed for rotation with a first shaft which in practice is the driving shaft, and the output shaft of the engine in the case of a motor vehicle, and the other coaxial part comprises a hub adapted to be fixed for rotation with a second shaft which in practice is the driven shaft and the transmission input shaft in the case of such a motor vehicle.
Such a torsion damping assembly ensures a regular or uniform torque transmission to one of the coaxial part when the other coaxial part is subjected to rotational torque, i.e., in case of a motor vehicle, to filter vibrations which are capable of developing along the kinematic chain running from the engine to the driven wheels of the vehicle.
Most often the resilient means circumferentially interposed between the coaxial parts of such a torsion damping assembly comprise coil springs which are each arranged chordally of a circumference of the assembly and, partly in an opening or window formed in an annular component which belongs to one of the coaxial parts and partly in an opening or window formed in another component, e.g., an annular member, which is parallel to the annular component, and part of the other of the coaxial parts.
It has, however, been proposed, notably in French patent publication No. 2,493,447 in the name of the assignee of the present application, to employ as at least a part of the resilient means at least one resiliently deformable arm which extends circumferentially from a support member fixed for rotation with one of the coaxial parts and attached at its end to the other coaxial part.
In practice such a resiliently deformable arm and its support may advantageously be formed by suitably cutting out a single blank of sheet metal so that the construction is particularly economical and the axial arrangement spares the coaxial parts and/or provides additional place in the coaxial parts for the other resilient means.